TX6 Release 2013-04-22

[karo-tx-uboot.git] / arch / arm / imx-common / timer.c

diff --git a/arch/arm/imx-common/timer.c b/arch/arm/imx-common/timer.c
index ab37d641ece97c82f230ad9e6a89511fea8fddff..b2ce8fee1777a6afcc30099000d389652fd92c71 100644 (file)
--- a/arch/arm/imx-common/timer.c
+++ b/arch/arm/imx-common/timer.c
@@ -29,6 +29,8 @@
 #include <asm/arch/imx-regs.h>
 #include <asm/arch/clock.h>
 
+#define DEBUG_TIMER_WRAP
+
 /* General purpose timers registers */
 struct mxc_gpt {
        unsigned int control;
@@ -43,28 +45,64 @@ static struct mxc_gpt *cur_gpt = (struct mxc_gpt *)GPT1_BASE_ADDR;
 /* General purpose timers bitfields */
 #define GPTCR_SWR              (1 << 15)       /* Software reset */
 #define GPTCR_FRR              (1 << 9)        /* Freerun / restart */
-#define GPTCR_CLKSOURCE_32     (4 << 6)        /* Clock source */
+#define GPTCR_CLKSOURCE_IPG    (1 << 6)        /* Clock source */
+#define GPTCR_CLKSOURCE_CKIH   (2 << 6)
+#define GPTCR_CLKSOURCE_32kHz  (4 << 6)
+#ifdef CONFIG_MX6Q
+#define GPTCR_CLKSOURCE_OSC_DIV_8      (5 << 6)
+#define GPTCR_CLKSOURCE_OSC    (7 << 6)
+#else
+#define GPTCR_CLKSOURCE_OSC    (5 << 6)
+#endif
+#define GPTCR_CLKSOURCE_MASK   (7 << 6)
 #define GPTCR_TEN              1               /* Timer enable */
 
+#if 1
+#define GPT_CLKSOURCE          GPTCR_CLKSOURCE_OSC
+#define GPT_REFCLK             24000000
+#define GPT_PRESCALER          24
+#else
+#define GPT_CLKSOURCE          GPTCR_CLKSOURCE_32kHz
+#define GPT_REFCLK             32768
+#define GPT_PRESCALER          1
+#endif
+#define GPT_CLK                        (GPT_REFCLK / GPT_PRESCALER)
+
+#ifdef DEBUG_TIMER_WRAP
+/*
+ * Let the timer wrap 30 seconds after start to catch misbehaving
+ * timer related code early
+ */
+#define TIMER_START            (-time_to_tick(30 * CONFIG_SYS_HZ))
+#else
+#define TIMER_START            0UL
+#endif
+
 DECLARE_GLOBAL_DATA_PTR;
 
-#define timestamp (gd->arch.tbl)
-#define lastinc (gd->arch.lastinc)
+static inline unsigned long tick_to_time(unsigned long tick)
+{
+       unsigned long long t = (unsigned long long)tick * CONFIG_SYS_HZ;
+       do_div(t, GPT_CLK);
+       return t;
+}
 
-static inline unsigned long long tick_to_time(unsigned long long tick)
+static inline unsigned long time_to_tick(unsigned long time)
 {
-       tick *= CONFIG_SYS_HZ;
-       do_div(tick, MXC_CLK32);
+       unsigned long long ticks = (unsigned long long)time;
 
-       return tick;
+       ticks *= GPT_CLK;
+       do_div(ticks, CONFIG_SYS_HZ);
+       return ticks;
 }
 
-static inline unsigned long long us_to_tick(unsigned long long usec)
+static inline unsigned long us_to_tick(unsigned long usec)
 {
-       usec = usec * MXC_CLK32 + 999999;
-       do_div(usec, 1000000);
+       unsigned long long ticks = (unsigned long long)usec;
 
-       return usec;
+       ticks *= GPT_CLK;
+       do_div(ticks, 1000 * CONFIG_SYS_HZ);
+       return ticks;
 }
 
 int timer_init(void)
@@ -79,15 +117,18 @@ int timer_init(void)
        for (i = 0; i < 100; i++)
                __raw_writel(0, &cur_gpt->control);
 
-       __raw_writel(0, &cur_gpt->prescaler); /* 32Khz */
+       __raw_writel(GPT_PRESCALER - 1, &cur_gpt->prescaler);
 
        /* Freerun Mode, PERCLK1 input */
        i = __raw_readl(&cur_gpt->control);
-       __raw_writel(i | GPTCR_CLKSOURCE_32 | GPTCR_TEN, &cur_gpt->control);
+       i &= ~GPTCR_CLKSOURCE_MASK;
+       __raw_writel(i | GPT_CLKSOURCE | GPTCR_TEN, &cur_gpt->control);
 
        val = __raw_readl(&cur_gpt->counter);
-       lastinc = val / (MXC_CLK32 / CONFIG_SYS_HZ);
-       timestamp = 0;
+       gd->arch.lastinc = val;
+       gd->arch.tbu = 0;
+       gd->arch.tbl = TIMER_START;
+       gd->arch.timer_rate_hz = GPT_CLK;
 
        return 0;
 }
@@ -95,19 +136,11 @@ int timer_init(void)
 unsigned long long get_ticks(void)
 {
        ulong now = __raw_readl(&cur_gpt->counter); /* current tick value */
+       ulong inc = now - gd->arch.lastinc;
 
-       if (now >= lastinc) {
-               /*
-                * normal mode (non roll)
-                * move stamp forward with absolut diff ticks
-                */
-               timestamp += (now - lastinc);
-       } else {
-               /* we have rollover of incrementer */
-               timestamp += (0xFFFFFFFF - lastinc) + now;
-       }
-       lastinc = now;
-       return timestamp;
+       gd->arch.tbl += inc;
+       gd->arch.lastinc = now;
+       return gd->arch.tbl;
 }
 
 ulong get_timer_masked(void)
@@ -118,25 +151,38 @@ ulong get_timer_masked(void)
         * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
         * 5 * 10^6 days - long enough.
         */
+       /*
+        * LW: get_ticks() returns a long long with the top 32 bits always ZERO!
+        * Thus the calculation above is not true.
+        * A 64bit timer value would only make sense if it was
+        * consistently used throughout the code. Thus also the parameter
+        * to get_timer() and its return value would need to be 64bit wide!
+        */
        return tick_to_time(get_ticks());
 }
 
 ulong get_timer(ulong base)
 {
-       return get_timer_masked() - base;
+       return tick_to_time(get_ticks() - time_to_tick(base));
 }
 
+#include <asm/gpio.h>
+
 /* delay x useconds AND preserve advance timstamp value */
 void __udelay(unsigned long usec)
 {
-       unsigned long long tmp;
-       ulong tmo;
+       unsigned long start = __raw_readl(&cur_gpt->counter);
+       unsigned long ticks;
+
+       if (usec == 0)
+               return;
 
-       tmo = us_to_tick(usec);
-       tmp = get_ticks() + tmo;        /* get current timestamp */
+       ticks = us_to_tick(usec);
+       if (ticks == 0)
+               ticks++;
 
-       while (get_ticks() < tmp)       /* loop till event */
-                /*NOP*/;
+       while (__raw_readl(&cur_gpt->counter) - start < ticks)
+               /* loop till event */;
 }
 
 /*
@@ -145,5 +191,5 @@ void __udelay(unsigned long usec)
  */
 ulong get_tbclk(void)
 {
-       return MXC_CLK32;
+       return gd->arch.timer_rate_hz;
 }